I have one small suggestion as a fellow New Yorker, try Tempvs Fvgit on 25th St. Small place but the proprietor knows his Heuers fairly well, really enjoys discussing them and has a small selection of vintage watches that usually includes a Heuer or two.
And, any chance a maybe less-knowledgeable but still enthusiastic Heuer collector might join you gents on one of your sojourns? :)